As the ALPINE galaxies are rather mature in terms of their stellar mass and ISM properties, it might not be very surprising to find a relatively large dust attenuation in this population. The most massive galaxies in the sample have a similar fraction of dust-obscured star formation as galaxies at the peak of cosmic SFR density [1]}. The measurement of dust mass at this early epoch places constraints on the dust production mechanisms and chemical evolution models. The analysis of ages and dust masses by [2]} draws the picture that these galaxies are likely the progenitors of bulge-dominated spiral or elliptical galaxies at lower redshifts. The dust production has to occur quickly, in line with the evolution of proto-spheroids [3]}. Dust production by supernovae on short time scales provide the most likely scenario for the high dust masses of these \(z=\)  4–6 galaxies [4]}, [5]}. However, it is interesting that current models have difficulties to reproduce the high dust-mass to stellar-mass ratios (\(\ge \)\(0.03\) ) of young \(z\)\(\sim \) 5–6 galaxies with high sSFRs (\(\ge 40\,{\rm Gyr^{-1}}\) ) [5]}. This becomes even more intriguing with the discovery of entirely optically dark galaxies at \(z\)\(\sim \)\(6.7\)  and \(z\)\(\sim \)\(7.4\)  [7]}, [8]} from the REBELS sample (the \(z>6\)  continuation of ALPINE, see survey overview described in [9]}), although there could be significant uncertainties in the stellar masses (hence, the dust to stellar mass ratios) of these galaxies (Sommogivo et al. in prep.). Such dust-obscured galaxies at high redshifts challenge current dust formation models and at the same time suggest that rest-UV observations are still missing a substantial amount (\(\sim \) 10–25%) of galaxies contributing to the cosmic SFR density at \(z>6\)  [7]}.
